Question

A liquid having coefficient of viscosity 0.02 decapoise is filled with a container of cross sectional area 20 $m^2$. If the viscous drag between two adjacent layer in flowing is 1 N. Then the viscosity gradient is :

• A. $2s^{-1}$
• B. $2.5s^{-1}$
• C. $3s^{-1}$
• D. $3.5s^{-1}$

Answer 1

Answer: (B)

$2.5s^{-1}$

$\text{we know that}$

$\eta =\frac{f/A}{\frac{dv}{dl}}\Rightarrow \frac{dv}{dl}=\frac{f}{A\eta }$

$=\frac{1}{0.02\times 20}=2.5s^{-1}$

$\text{Answerl- (B)}$